CN1237786A - Method and device for visual inspection of objects - Google Patents

Abstract

A pickup device (30) to which a plurality of reflective surfaces (42, 44, 46, 48) are attached. The pick-up device (30) can pick up an object (38) and can move the object (38) over a light source (51). These reflective surfaces (42, 44, 46, 48) are capable of reflecting light beams (61) emitted from the light source (51), and the deflected light beams (63, 65, 67, 69) produced by them can illuminate the object (38) from behind. These deflected beams (63, 65, 67, 69) can produce multiple contour images of the object (38) in multiple cameras (52, 54, 56, 58). Visual inspection of objects (38) can be performed by analyzing these images.

Description

Method and device for visual inspection of objects

The present invention generally relates to visual detection of objects. In particular, the present invention relates to an apparatus and process for visual inspection of objects.

In general, workpieces such as semiconductor devices need to be visually inspected to ensure that they meet the parameters required by design specifications, such as lead coplanarity, lead length, lead straightness, mark inspection, surface inspection, lead spacing, etc. wait. Visual inspection of semiconductor devices is generally performed using a visual inspection bench. Semiconductor devices are placed on a visual inspection table. Using front-illumination technology or back-illumination technology, an image of the semiconductor device can be formed and analyzed by an image computer. If the semiconductor device meets predetermined design specifications, it passes this test and proceeds to the next stage of the manufacturing process. Otherwise, it is discarded. Traditional visual inspection processes can disrupt semiconductor device handling and are often time-consuming. Additionally, it is difficult to combine traditional visual inspection processes with cost-effective and time-saving automated device handling.

Accordingly, it would be desirable to have an apparatus and method that would enable the visual inspection of objects in an automated process for handling the objects. This method should be simple and time-saving. And the device should also be inexpensive. Additionally, the device is preferably compatible with existing object manipulation equipment and procedures.

Fig. 1 isometrically shows a device for visual inspection of an object according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram of a system using the apparatus for visual inspection of an object according to the first embodiment of the present invention as shown in FIG. 1 .

Fig. 3 is a cross-sectional view of an apparatus for visual inspection of an object according to a second embodiment of the present invention.

FIG. 4 is a schematic diagram of a system using the apparatus for visual inspection of an object according to the second embodiment of the present invention as shown in FIG. 3 .

Fig. 5 isometrically shows a device for visual inspection of an object according to a third embodiment of the present invention.

It should be understood that, for the sake of clarity and simplicity of the drawings, they have not been drawn to scale. It should also be appreciated that for convenience, reference numerals have been repeated among the figures to represent corresponding or analogous components.

In summary, the present invention provides an apparatus and method enabling visual inspection of objects during automated object handling. According to the invention, the objects are picked up by a pick-up device. When the pick-up is in a predetermined position relative to the light source, the light source will illuminate a portion of the pick-up adjacent to the object. However, according to one embodiment, a deflector on the pick-up device can reflect a part of the incident light beam from the light source to form a deflected light beam. The deflected light back illuminates the object in a first direction and forms a first outline of the object. A further part of the incident light beam illuminates the object from behind in a second direction and forms a second contour of the object. The first and second contour images of the object have different viewing directions. According to another embodiment of the present invention, multiple deflectors attached to the pickup device can reflect different parts of the incident beam and generate multiple deflected beams in different directions. These deflected beams illuminate different parts of the object from the back and generate corresponding contour patterns. In both embodiments, the position and orientation of a reflective surface relative to the pick-up device is fixed and can be precisely determined. Thus, the pick-up device can act as a frame of reference when the graphics computer reconstructs the image of the object and checks the geometry of the object. Therefore, visual inspection can be achieved while the pick-up device picks up the object and moves it from one place to another. More specifically, objects do not need to be placed on an inspection table for visual inspection.

FIG. 1 isometrically shows a visual detection device 10 according to a first embodiment of the present invention. Device 10 includes a rod 12 . On one end of the rod 12 there is an object pick-up mechanism 14 . The pick-up mechanism 14 in this embodiment is a vacuum mechanism. A shaft 16 surrounds a portion of the rod 12 . Rod 12 and sleeve 16 may be made of metal, plastic or the like. The rod 12 and the sleeve 16 can be made in one piece or can also be made in two parts which are joined together. The sleeve 16 has a beveled end face at a distance from one end of the rod 12 . A reflective surface 15 is formed on this beveled end face of the sleeve 16 . The reflective surface 15 is used as a deflector for deflecting the light beam. In one embodiment, the sleeve 16 is made of metal and the sloped end face of the sleeve 16 is a polished metal surface, which acts as the sloped reflective surface 15 . In another embodiment, the inclined reflective surface 15 is formed by attaching a mirror on the inclined end surface of the sleeve 16 . In this embodiment, the included angle between the normal (not shown) of the inclined reflective surface 15 and the direction parallel to the rod 12 (the vertical direction in FIG. 1 ) is about 45 degrees (°). The geometric parameters of the device 10, such as the position and orientation of the sloped reflective surface 15 relative to the pick-up mechanism 14 located above the end of the rod 12, are preferably determined with high precision. Thus, when device 10 picks up an object during visual inspection, the object's position and orientation relative to device 10 can be accurately determined using a feature (such as the edge of reflective surface 15) that can serve as a reference position.

The function of the apparatus 10 is to pick up an object (such as a semiconductor device) and move it from one place to another. During the movement of the object, the visual detection of the object is performed. Therefore, the device 10 can also be referred to as a visual inspection device or a pick-up device. It should be understood that FIG. 1 only shows a part of the device 10 related to the visual detection of objects. The device 10 also includes an operating system (not shown), such as an electro-mechanical system, a hydraulic system, a pneumatic system, and the like. The system is used to pick up, move and release objects. It should also be understood that the structure of the device 10 is not limited to the content described above and shown in FIG. 1 . For example, pick-up mechanism 14 is not limited to being a vacuum mechanism. Any mechanism capable of picking up the object to be measured (such as: a buckle mechanism, a locking mechanism, a magnetic mechanism, etc.) can be used as the pickup mechanism 14 of the device 10 . Rod 12 and sleeve 16 are also not limited to having the right-angle cross-section shown in FIG. 1 . The cross-section of the rod 12 and sleeve 16 can have any shape, such as circular, oval, triangular, pentagonal, hexagonal, etc. Additionally, the sleeve 16 in the device 10 is optional. In an alternative embodiment of the invention (not shown), the device 10 does not contain the sleeve 16 and the sloped reflective surface 15 is formed by attaching a reflective plane such as a mirror directly to the rod 12 . Additionally, device 10 may contain one or more reference marks (not shown) on sloped reflective surface 15 . These reference marks may facilitate accurate measurements of the position and orientation of an object relative to device 10 .

FIG. 2 schematically shows a system 20 including the apparatus 10 shown in FIG. 1 for visual inspection of an object 18 according to a first embodiment of the present invention. System 20 may also be referred to as an optical system or a detection system. In this embodiment, object 18 is a semiconductor device. During a packaging process of the semiconductor device, the apparatus 10 picks up the semiconductor device 18 from one location and transfers it to another location. Detection system 20 also includes a light source 21 and cameras 22 and 24 . In one embodiment, the light source 21 is a light source capable of emitting continuous light (such as a light emitting diode). During the movement of semiconductor device 18, apparatus 10 will stay in a position relative to light source 21 and cameras 22 and 24 (shown in FIG. 1) for a short time interval (eg, 0.25 seconds). Cameras 22 and 24 record contour images of semiconductor device 18 during this time interval. In another embodiment, the light source 21 is a pulsed light source that emits a pulsed light beam when the device 10 is moved to the position shown in FIG. 2 . Cameras 22 and 24 record images of the profile of semiconductor device 18 formed by the pulsed beam. An image computer (not shown) connected to cameras 22 and 24 will analyze the image and check out the geometry of semiconductor device 18 and its position and orientation relative to device 10 .

During visual inspection, a beam of light 25 emitted by light source 21 may at least partially illuminate device 10 and semiconductor device 18 . In this embodiment, beam 25 is a substantially collinear beam which is substantially perpendicular to rod 12 . A portion 26 of the light beam 25 is reflected by the inclined reflective surface 15 , thereby producing a deflected light beam 27 substantially parallel to the rod 12 . The deflected light beam 27 illuminates the semiconductor component 18 from behind and forms a profile image in the camera 22 . A portion 28 of the light beam 25 directly illuminates the semiconductor component 18 and forms a contour image in the camera 24 . The contour image of the semiconductor component 18 formed by the deflected light beam 27 and the contour image of the semiconductor component 18 formed by the portion 28 of the light beam 25 have different viewing directions. As shown in FIG. 2 , deflected beam 27 provides a top view of semiconductor device 18 , while portion 28 of beam 25 provides a side view of semiconductor device 18 . An image computer (not shown) connected to the cameras 22 and 24 can analyze the two images and check various parameters of the semiconductor device 18, such as lead coplanarity, lead length, lead straightness, mark detection, Surface inspection, lead spacing, and more. If they do not meet predetermined design specifications, semiconductor devices 18 are discarded. After the visual inspection is complete, the rejected parts are moved to a predetermined location for disposal.

It should be noted that when the device 10 picks up the semiconductor device 18, the relative position and orientation of the semiconductor device 18 and the device 10 will often change. Such changes typically result in changes in the orientation and position of the semiconductor device 18 in its final position, which poses problems for packaging processes that require greater accuracy in the final position and orientation of the semiconductor device 18 . The visual inspection process of the present invention can solve this problem. Preferably, the images from cameras 22 and 24 also include an image of a portion of device 10 in accordance with the present invention. Since the geometric parameters of the device 10 (for example: the position and direction of the inclined reflective surface 15 relative to the pick-up mechanism 14) are determined with high precision, the position and orientation of the semiconductor device 18 relative to the device 10 can be provided by analyzing these images. Precise data about orientation. These data can be used to adjust the position and orientation of the device 10 when the device 10 releases the semiconductor device 18, thereby bringing the semiconductor device 18 to a precise position and orientation in its final position.

It should be understood that the structure and operation of the detection system 20 are not limited to those described above. For example, the light source 21 can also be a diffuse light source. Alternatively, detection system 20 could contain a deflector (not shown) and cameras 22 and 24 could be replaced with a single camera (not shown). The deflector may consist of one or more lenses, one or more mirrors, or a combination of lenses and mirrors. The deflector may deflect the deflected light 27, the portion 28 of the beam 25, or both beams after they pass through the semiconductor device 18 to produce two imaging beams substantially parallel to each other. Thus, two profile images of semiconductor device 18 with two different viewing directions can be formed in one camera.

Fig. 3 is a cross-sectional view of a visual inspection device 30 according to a second embodiment of the present invention. Device 30 includes a rod 32 . At one end of the rod 32 there is an object pickup mechanism 34 . The pick-up mechanism 34 in this embodiment is a vacuum mechanism. The function of the device 30 is to pick up an object (such as a semiconductor device) and move it from one location to another. During the movement of the object, the visual detection of the object is performed. Therefore, the device 30 can also be referred to as a visual inspection device or a pick-up device. A rectangular ferrule 36 surrounds a portion of the rod 32 . Rod 32 and ferrule 36 may be made of metal or plastic or the like. The ferrule 36 can be mounted on the rod 32 or can be integrally formed with the rod 32 . On opposite sides of ferrule 36 are attached reflective surface 42 and reflective surface 44 . The included angle between the respective normals (not shown) of the reflective surfaces 42 and 44 and the direction parallel to the rod 32 (the vertical direction in FIG. 3 ) is about 5° to 30°. The range between these two angles is preferably between about 5° and 27°. The values of these two angles depend on the size and shape of the device 30 and the position of the camera (as shown in Figure 4). In one embodiment, the two included angles are approximately 17.5°. These two included angles are preferably approximately equal. Thus, reflective surfaces 42 and 44 will form a substantially symmetrical feature of device 30 relative to rod 32 . Reflective surface 46 and reflective surface 48 are connected to reflective surfaces 42 and 44 respectively. The angle between the normal (not shown) of the reflective surface 46 and the direction parallel to the rod 32 is preferably greater than the angle between the normal of the reflective surface 42 and the direction parallel to the rod 32 . The difference between these two included angles is approximately between 5° and 30° and preferably at least 13°. Similarly, the angle between the normal (not shown) of reflective surface 48 and the direction parallel to rod 32 is preferably greater than the angle between the normal of reflective surface 44 and the direction parallel to rod 32 . Reflective surfaces 46 and 48 are preferably substantially symmetrical with respect to rod 32 . In this way, the angle between the normal of the reflective surface 46 and the direction parallel to the rod 32 and the angle between the normal of the reflective surface 48 and the direction parallel to the rod 32 will be approximately equal. In this embodiment, the two included angles are approximately between 10° and 45°. The range of these two included angles is preferably between about 30° and 42°. The value of these two angles depends on the geometry of the device 30 and the position of the camera (as shown in FIG. 4 ). In one embodiment, both included angles are approximately 37.5°. Reflective surfaces 42, 44, 46 and 48 all function as deflectors and may be polished metal surfaces, mirror surfaces, or the like. In addition, device 30 contains reference marks 43, 45, 47 and 49 on reflective surfaces 42, 44, 46 and 48, respectively. The geometric parameters of the device 30 (such as: the position and orientation of the reflective surfaces 42, 44, 46 and 48 relative to the pick-up mechanism 34 and the reference marks 43, 45, 47 and 49 on the corresponding reflective surfaces 42, 44, 46 and 48 position) is preferably determined with high precision. Thus, when device 30 picks up an object during a visual inspection process, the position and orientation of the object relative to device 30 can be accurately determined.

It should be understood that FIG. 3 only shows a part of the device 30 related to the visual detection of objects. The device 30 also includes an operating system (not shown), such as an electro-mechanical system, a hydraulic system, a pneumatic system, and the like. The system is used to pick up, move and release objects. It should also be understood that the structure of the device 30 is not limited to the above. For example, pick-up mechanism 34 is not limited to being a vacuum mechanism. Any mechanism capable of picking up the object to be sided (such as: a buckle mechanism, a locking mechanism, a magnetic mechanism, etc.) can be used as the picking mechanism 34 of the device 30 . In an alternative embodiment (not shown), device 30 does not contain ferrule 36 and reflective surfaces 42 and 44 are attached directly to rod 32 . Additionally, device 30 is not limited to having only four reference numerals 43 , 45 , 47 and 49 . Device 30 may have any number of reference labels, such as 0, 1, 2, 3, 4, 5, 6, 7, 8, and so on. In an embodiment where device 30 does not contain any reference marks, the position and orientation of the object relative to device 30 can be determined by utilizing other features on device 30, such as the corners of reflective surfaces 42, 44, 46 and 48, the reflective The connection line between surfaces 42 and 46, the connection line between reflective surfaces 44 and 48, and so on. In addition, the device 30 is not limited to having only four reflective surfaces. In various alternative embodiments (not shown), device 30 may contain 1 reflective surface (such as reflective surface 42), 2 reflective surfaces (such as reflective surfaces 42 and 44 or reflective surfaces 42 and 46), or 3 reflective surfaces. Surfaces (such as reflective surfaces 42, 44 and 46). In these alternate embodiments, it is preferable to adjust the number, location and orientation of the cameras in device 30 accordingly.

FIG. 4 schematically shows a system 50 including the apparatus 30 shown in FIG. 3 for visual inspection of an object 38 according to a second embodiment of the present invention. System 50 may also be referred to as an optical system or a detection system. In this embodiment, the object 38 is a semiconductor device having two sets of leads 37 and 39 on opposite sides thereof. During the semiconductor device packaging process, apparatus 30 picks up semiconductor device 38 from one location and moves it to another location. Detection system 50 also includes a light source 51 and cameras 52 , 54 , 56 and 58 . Similar to the light source 21 in the detection system 20 shown in FIG. 2 , the light source 51 can be a light source capable of emitting continuous light (such as a light emitting diode), or a pulsed light source. The cameras 52 , 54 , 56 and 58 are capable of recording respective profile images of the semiconductor device 38 formed by the light beam 61 emitted by the light source 51 . An image computer (not shown) connected to cameras 52 , 54 , 56 and 58 can analyze the images and can examine the geometry of semiconductor device 38 and its position and orientation relative to device 30 .

Light beam 61 emitted by light source 51 is capable of illuminating reflective surfaces 42 , 44 , 46 and 48 of device 30 during visual inspection. In this embodiment, beam 61 is a substantially collinear beam that is substantially parallel to rod 32 . A portion 62 of beam 61 is reflected by reflective surface 42 and thus produces a deflected beam 63 which illuminates lead set 37 of semiconductor device 38 from the back and forms an outline image thereof in camera 52 . Instead, a portion 66 of the light beam 61 is reflected by the reflective surface 46 and thus produces a deflected light beam 67 which illuminates the lead set 37 of the semiconductor device 38 from the back and forms an outline image thereof in the camera 56 . The contour images of lead wire set 37 formed by deflected light beams 63 and 67 have mutually different viewing directions. The image formed by deflected beam 63 is sometimes referred to as a deep view of lead set 37 , while the image formed by deflected beam 67 is sometimes referred to as a shallow view of lead set 37 . Similarly, a portion 64 and 68 of light beam 61 is reflected by reflective surfaces 44 and 48 respectively and thus produces deflected light beams 65 and 69, respectively, which illuminate the lead set 39 of semiconductor device 38 from the back and appear in camera 54 and Contour image is formed in 58 . The profile images of lead wire set 39 formed by deflected light beams 65 and 69 have mutually different viewing directions. Instead, the images formed by deflected beams 65 and 69 are sometimes referred to as deep and shallow views of lead set 39, respectively.

A graphics computer (not shown) connected to the cameras 52, 54, 56 and 58 can analyze the profile images and can detect various parameters of the semiconductor device 38, such as lead coplanarity, lead length, lead straightness, mark detection , surface inspection, lead spacing, and more. If they do not meet predetermined design specifications, semiconductor devices 38 are discarded. After the visual inspection is complete, the rejected parts are moved to a predetermined location for disposal.

It should be noted that when the device 30 picks up the semiconductor device 38, the relative position and orientation of the semiconductor device 38 and the device 30 will often change. Such changes typically result in changes in the orientation and position of the semiconductor device 38 in its final position, which poses problems for packaging processes that require greater accuracy in the final position and orientation of the semiconductor device 38 . The visual inspection process of the present invention can solve this problem. According to the present invention, the images of the cameras 52, 54, 56, and 58 preferably also include images of the reference markers 43, 45, 47, and 49, respectively. Due to the geometric parameters of the device 30 (for example: the position and orientation of the reflective surfaces 42, 44, 46 and 48 relative to the pick-up mechanism 34 and the positions of the reference marks 43, 45, 47 and 49 on the respective reflective surfaces 42, 44, 46 and 48 position) is determined with high precision, so analysis of these images can provide precise data on the position and orientation of semiconductor device 38 relative to device 30. These data can be used to adjust the position and orientation of the device 30 when the device 30 releases the semiconductor device 38, thereby bringing the semiconductor device 38 to a precise position and orientation in its final position.

It should be understood that the structure and operation of the detection system 50 are not limited to those described above. For example, the light source 51 may also emit a diffuse beam. Also, in an alternate embodiment, detection system 50 contains a set of deflectors (not shown) and cameras 52, 54, 56 and 58 are replaced by a single camera (not shown). These deflectors may be formed from multiple lenses, multiple mirrors, or a combination of multiple lenses and mirrors. These deflectors may deflect the deflected beams 63, 65, 67 and 69 after they pass through the semiconductor device 38 to produce four imaging beams that are substantially parallel to each other. Thus, four profile images of the semiconductor device 38 with different viewing directions can be formed in one camera. In another alternative embodiment, the detection system 50 contains two cameras (not shown). The first camera replaces cameras 52 and 56 and the second camera replaces cameras 54 and 58 . The deflected beams 63 and 67 are deflected to form two image beams substantially parallel to each other, thereby forming a deep view and a shallow view, respectively, of the lead set 37 in the first camera. Deflected beams 65 and 69 are deflected to form two image beams substantially parallel to each other to form deep and shallow views, respectively, of lead set 39 in the second camera.

FIG. 5 isometrically shows a detection device 70 for visual detection of an object 81 according to a third embodiment of the present invention. Device 70 is similar in structure and function to device 30 shown in FIG. 3 . The device 70 is also referred to as a vision inspection device or a pick-up device. Similar to device 30 shown in FIG. 3 , device 70 includes a rod 32 , an object pick-up mechanism 34 , ferrule 36 , reflective surfaces 42 , 44 , 46 and 48 and reference marks 43 , 45 , 47 and 49 . Additionally, device 70 includes reflective surfaces 72 and 74 attached to both sides of ferrule 36 and between reflective surfaces 42 and 44 . The angle between each normal (not shown) of the reflective surfaces 72 and 74 and the direction parallel to the rod 32 (the vertical direction in FIG. 5 ) is approximately between 5° and 30°. Reflective surface 76 and reflective surface 78 are connected to reflective surfaces 72 and 74, respectively. The angle between the normal (not shown) of the reflective surface 76 and the direction parallel to the rod 32 is preferably greater than the angle between the normal of the reflective surface 72 and the direction parallel to the rod 32 . Similarly, the angle between the normal (not shown) of reflective surface 78 and the direction parallel to rod 32 is preferably greater than the angle between the normal of reflective surface 74 and the direction parallel to rod 32 . In this embodiment, the two included angles are approximately between 10° and 45°. Device 70 preferably includes reference marks 73, 75, 77 and 79 on reflective surfaces 72, 74, 76 and 78, respectively. Similar to reflective surfaces 42, 44, 46 and 48, reflective surfaces 72, 74, 76 and 78 function as deflectors and may be polished metal surfaces, mirrors or the like.

In a preferred embodiment, the four included angles between the normals of the reflecting surfaces 42, 44, 72 and 74 and the direction parallel to the rod 32 are completely equal, and the normals of the reflecting surfaces 46, 48, 76 and 78 are equal to The four included angles between the directions parallel to the rod 32 are also exactly equal. The geometric parameters of the device 70 (for example: the position and orientation of the reflective surfaces 42, 44, 46, 48, 72, 74, 76 and 78 relative to the pick-up mechanism 34 and the reference marks 43, 45, 47, 49, 73, 75, 77 and 79 on respective reflective surfaces 42, 44, 46, 48, 72, 74, 76 and 78) are preferably determined with high precision. Accordingly, the position and orientation of object 81 relative to device 70 can be accurately determined.

The process of visual inspection of object 81 using device 70 is similar to that described with reference to FIG. 4 . However, device 70 is capable of forming eight images of different parts of object 81 simultaneously. In this embodiment, the object 81 is a semiconductor device in a quadrangular package, and the four sides of the package have lead groups 82, 84, 86 and 88 respectively. During visual inspection, reflective surfaces 42 and 46 create two deflected beams that illuminate lead set 82 from behind and form a deep and shallow outline view of lead set 82, respectively. Reflective surfaces 44 and 48 generate two deflected beams that illuminate lead set 84 from behind and form a deep and shallow outline view of lead set 84, respectively. Reflective surfaces 72 and 76 generate two deflected beams that illuminate lead set 86 from behind and form a deep and shallow outline view of lead set 86, respectively. Reflective surfaces 74 and 78 produce two deflected beams that illuminate lead set 88 from behind and form a deep and shallow outline view of lead set 88, respectively.

By now it should be appreciated that an apparatus and method for visual inspection of objects in an automated process for handling objects has been provided. According to the invention, the object is picked up by a pick-up device which is endowed with optical properties. The pick-up device can be used as a detection device. The light source may be used to illuminate a portion of the pick-up device adjacent to the object when the pick-up device is in a predetermined position relative to the light source. A plurality of reflective surfaces attached to the pick-up device reflect portions of incident light emitted by the light source to generate a plurality of deflected light beams. These deflected beams illuminate parts of the object from the back and generate images of their silhouettes. The pick-up device can also be used as a frame check when the image computer reconstructs the image of the object and checks the geometric characteristics of the object. So, vision inspection can be done while the pick-up device picks up the object and moves it from one place to another. More specifically, objects do not need to be placed on an inspection table for visual inspection. By utilizing backside illumination techniques, the present invention provides images that are generally free of hot spots, cold spots, or other image distortions that often occur in images formed using frontside illumination techniques. Since the reflective surfaces on the pick-up are used to provide backlighting, their optical qualities (such as smoothness and flatness) do not need to be as high as those required for imaging lenses and mirrors. Therefore, the device according to the invention is easy and inexpensive to manufacture. Its method for performing visual inspections is also simple and time-saving. In addition, the detection process described in the present invention is also compatible with the existing object manipulation process.

Claims (10)

1. A visual inspection device, characterized in that it comprises a rod (12) having one end; an object pick-up mechanism (14) on the end of said rod (12); and A reflective surface (15) attached to said rod at a distance from said rod end. 2. The visual inspection device according to claim 1, wherein the angle between the reflective surface and the direction parallel to the rod is about 45 degrees. 3. The visual detection device according to claim 1, characterized in that it also includes a sleeve (16) surrounding a part of said rod and having an inclined end surface on which said reflective surface is formed. 4. The visual inspection device according to claim 3, characterized in that said sleeve (16) comprises a metal sleeve; and The reflective surface (15) comprises a polished metal surface. 5. 3. Visual inspection device according to claim 3, characterized in that said reflective surface (15) comprises a mirror attached to the beveled end surface of said sleeve. 6. A visual inspection device is characterized in that it comprises: a rod (12) having one end; an object pick-up mechanism (14) on the end of said rod (12); and A reflective surface (15) connected to the rod, the normal of the reflective surface forms an included angle with respect to the rod. 7. A method for visually detecting an object, comprising the steps of: Pick up the object with a pick-up device; generate a beam of light; deflecting a portion of the beam with a deflector on the pick-up to produce a first deflected beam; forming a first contour map of the first portion of the object having a first viewing direction by illuminating the first portion of the object with the first deflected light beam; A second contour map of the first portion of the object having a second viewing direction different from the first viewing direction is formed by utilizing a second portion of the light beam. 8. 7. The method of claim 7, further comprising the step of examining the geometry of the object using the first and second contour maps of the first portion of the object. 9. 7. The method of claim 7, wherein the step of generating the light beam includes the step of illuminating the pick-up device and the object with a pulsed light. 10. 7. The method of claim 7, wherein the step of forming a second profile of the first portion of the object includes the step of directly illuminating the object with the second portion of the light beam.

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